The uses of urethane polymer foams, whether flexible or rigid, are well known. They are used, for example, in furniture, transportation, bedding, textile laminates, carpet backing, packaging, insulation and flotation materials. Polyurethanes are made by the reaction of an isocyanate with a polyol. Ordinarily, the manufacturer of the urethane foam buys the reactive components in separate packages. One reactive component, commonly called the "A-side " component, contains the isocyanate. The other component, commonly called the "B-side" component, contains polyol, catalyst and other ingredients, e.g., surfactant, foaming agent, fire retardant and the like. The fire retardant may be admixed with either the A-side or B-side component, but if the fire retardant is capable of reacting with the isocyanate the fire retardant must be admixed with the B-side.
Unfortunately, a problem occurs in the incorporating a fire retardant, such as a phosphorus- or halogen-containing fire retardant, in the B-side component. The normal hydrolytic instability of such fire retardants leads to an increase in acidity in the mixture with a consequent increase in ionizable chlorine. The increased chlorine ion concentration deactivates the normally used tertiary amine catalysts and, thus, changes the characteristics of the foaming mechanism. Deactivation of the catalyst is due to reaction between the tertiary amine and the halogen- or phosphorus-containing fire retardant to form a quaternary ammonium salt. These deleterious effects do not occur immediately, but over a period of time. This results in a storage stability problem, i.e., prolonged storage of the B-side component, and concomitant deactivation of the catalyst followed by addition of the B-side component to the A-side component, yields a poor urethane polymer.
Accordingly, the present invention is directed to a B-side urethane polymer component, containing fire retardant, which is characterized by prolonged storage life.